It is known in the art to provide photographic material processors having a processing solution which is recirculated by a recirculation pump from a processing tank through a replenishment manifold, a filter and a heater. Conventional standard metering bellows pumps are used to add replenishing solution to the manifold for mixing with the recirculating solution. In recent low volume processors, replenishment may be added directly into a closed recirculation system and introduced either into the negative or positive pressure side of the recirculation pump.
If an additional component, such as a solid, paste or liquid chemical additive is to be used to alter or stabilize the chemical consistency, there is no specific provision to control the rate of exposure of the additional component to the recirculating solution in either the closed or open recirculation systems.